The epidemiology of fetal alcohol syndrome and partial FAS in a South African community

Abstract

Objectives

The prevalence and characteristics of fetal alcohol syndrome (FAS) and partial fetal alcohol syndrome (PFAS) were determined in a third primary school cohort in a community in South Africa (SA).

Methods

An active case ascertainment, two-tier screening methodology, and the revised Institute of Medicine diagnostic criteria were employed among 818 first grade pupils. Characteristics of children with FAS and PFAS are contrasted with a randomly selected control group. Data were collected and analyzed for children in the study regarding: (1) physical growth and development, including dysmorphology, (2) intelligence and behavioral characteristics, and (3) their mother's social, behavioral, and physical characteristics.

Results

The rate of FAS and PFAS in this area continues as the highest reported in any overall community and is much higher than rates elsewhere. In this cohort it is 68.0–89.2 per 1000. Severe episodic drinking on weekends among mothers of children with FAS and PFAS accounts for 96% of all alcohol consumed. Various measures of maternal drinking are significantly correlated with negative outcomes of children in the areas of non-verbal intelligence (−0.26), verbal intelligence (−0.28), problem behavior (0.31), and overall dysmorphology score (0.59). Significantly more FAS and PFAS exists among children of rural residents (OR = 3.79).

Conclusions

A high rate of FAS and PFAS was again documented in this community, and it has increased. Given population similarities, we suspect that other communities in the Western Cape Province of South Africa also have high rates. Programs for prevention are needed.

Introduction

Alcohol is a teratogen that has raised concerns about birth outcomes for years (Sullivan, 1899, Lemoine et al., 1968, Abel, 1998, Armstrong, 2003), but the diagnosis of fetal alcohol syndrome (FAS) was not formalized and published until 1973 (Jones and Smith, 1973). Further delineation of the diagnosis has occurred since then, and work on its nature and applications continues (Sokol and Clarren, 1989, Aase, 1994, Aase et al., 1995, Stratton et al., 1996, Astley and Clarren, 2000, Hoyme et al., 2005).

FAS is a pattern of anomalies and developmental deficits found in children exposed to large amounts of alcohol in the prenatal period. Children with FAS have a characteristic pattern of facial and body dysmorphology, delayed physical growth and development, and specific mental and behavioral deficits (Stratton et al., 1996). For a diagnosis of FAS, all three categories of problems must be present (Stratton et al., 1996), and the diagnosis should be made only after excluding other genetic and teratogenic anomalies (Hoyme et al., 2005). Even though a FAS diagnosis can be made without confirmation of maternal drinking (Stratton et al., 1996), a detailed maternal history is best to confirm the quantity, frequency, and timing of gestational drinking (May, 1995). In this study we provided diagnoses of two Institute of Medicine (IOM) prescribed fetal alcohol outcomes, FAS and partial fetal alcohol syndrome (PFAS) (Stratton et al., 1996). In addition to these two levels of fetal alcohol outcomes, the IOM report defined alcohol-related neurodevelopmental deficits (ARND) where the child has neurodevelopmental delays and/or behavioral problems with minimal dysmorphology characteristic of FAS or alcohol-related birth defects (ARBD) with some dysmorphology but minimal behavioral or neurodevelopmental problems consistent with FAS (Stratton et al., 1996). The entire continuum of effects, from mild to severe, is called fetal alcohol spectrum disorder (FASD).

In a first active case ascertainment study in this South African community, the rate of FAS among first grade children was 40.5–46.4 per 1000 (May et al., 2000). In a second, similar study it was even higher 2 years later at 65.2–74.2 per 1000 (Viljoen et al., 2005). Both of these rates of prevalence are the highest ever reported in the world.

FAS prevalence from clinic-based studies is estimated for the United States (US) as 0.33–2.2 (Abel and Sokol, 1991, Stratton et al., 1996, May and Gossage, 2001), and an average estimate for the developed world is 0.97 per 1000 (Abel and Sokol, 1987, Abel, 1998). A clinic-based rate of FAS for African Americans of low socioeconomic status (SES) has been reported as 2.3 per 1000 (Abel, 1998, Abel, 1995). In a few high risk American Indian reservation communities in the US, the prevalence of FAS has been researched via studies utilizing active case ascertainment methods, and averages of 8 per 1000 have been found. The short-term prevalence in these populations sometimes exceeds 20 per 1000 (Abel, 1995, May, 1991, May et al., 1983, May et al., 2002).

Active case ascertainment for FAS epidemiological research, where outreach and aggressive case finding are practiced, was endorsed by a study committee of the US Institute of Medicine as the most accurate approach to ascertaining prevalence; but such studies are logistically challenging, expensive, and time consuming (Stratton et al., 1996). Nevertheless, estimations of FAS prevalence and most of the delineation of the characteristics of all levels of FASD in the US come from various other sources: birth records, disability registries, clinic-based studies, and a very few population-based initiatives (Chavez et al., 1988, Stratton et al., 1996, May, 1996, Burd et al., 1996, Egeland et al., 1995, Egeland et al., 1998, Kvigne et al., 2004). All but one of the four active case ascertainment studies of FASD in the US, where outreach in major geographical areas focuses on aggressive case finding, were carried out among American Indians (Quaid et al., 1993, Duimstra et al., 1993, May et al., 1983, Clarren et al., 2001). Passive, record-based systems and clinic-based methods, which investigate FAS among clients presenting for medical services (e.g., prenatal clinics) are most commonly used in studies of other US and European populations (Abel and Sokol, 1991, Abel and Sokol, 1987, Abel, 1995, May, 1996, Chavez et al., 1988, Egeland et al., 1995, Egeland et al., 1998). Therefore, because of wide variation in methodologies, comparison of FAS prevalence and the characteristics of children with FASD is difficult to impossible.

Fruit orchards, grape-growing, wine production, and agriculture dominate large areas of Western Cape Province (WCP) of South Africa (SA). Wine production and unique social, and economic conditions over the past 300 years have influenced the modal drinking patterns. Wine was historically distributed daily by farmers to workers as partial payment for labor among an impoverished labor force. This practice was called the “Dop” system. Dop was outlawed over the past 40 years by multiple statutes, and there is widespread public sentiment against it. In our last study of this area, less than 2% of mothers of FAS children reported receiving Dop. But residual patterns of frequent, heavy, episodic alcohol consumption (now commercially purchased) by some individuals and groups remain a legacy of the Dop system. In recent years there have been changes in the nature of the drinking behavior of the worker population, as increased contemporary availability of inexpensive commercial beer, wine, and liquor, primarily in “take-away” (carry-out) sources and shebeens (illegal bars), has maintained or exacerbated heavy, episodic drinking behavior (London et al., 1995, Parry and Bennetts, 1998, London, 2000, Crome and Glass, 2000, Mager, 2004). Episodic (binge) drinking is a major form of recreation among sub-segments of the WCP population, which contributes to many public health problems (King et al., 2004).

The population of the WCP is four million people composed of: 57% cape coloured (mixed race), 18% black, 25% white, and 1% other. The Cape Town metropolitan area is the principal urban area of the WCP, but 40% of the population lives outside of it in small towns and rural areas. The study community is similar in social and economic character to many others in the Winelands of WCP, with a 1996 population of 45,255 (28.1% rural) (RSA, 1997). Most of the inhabitants of this area are coloured (people of mixed ancestry from intermarriage of black African populations, European-origin whites, and some Asians).

This article summarizes a third, active case ascertainment FAS research initiative in a first grade cohort in the WCP. Although FAS had been diagnosed in SA before (Palmer, 1985), a first population-based study in this community was prompted by a bi-national (US and SA) commission initiated by the vice presidents of the two countries (NIAAA, 1996, NIAAA, 1998). A follow-up study was undertaken in 1999, and both waves of research revealed the highest rates of FAS ever reported. While answering a number of questions about the nature and causes of FAS in this community in general, other questions were raised or were reframed by the findings (May et al., 2000, Viljoen et al., 2003, Viljoen et al., 2005). The study reported upon here was designed to further explore and summarize the epidemiology, maternal risk, child characteristics, trends, and etiology of FAS and PFAS in this community and on FASD in other human populations as well.